1. Field of Invention
The present invention relates to a caption removal method. More particularly, the present invention relates to a caption removal method for a digital video editing system.
2. Description of Related Art
Films nowadays can be spread rapidly through a variety of media, but some unwanted objects, such as strangers, advertising subtitles, etc, are often presented in films. One kind of unwanted objects seen more often is the captions embedded in films, and these captions often are unwanted ads. To be able to remove these objects, technologies regarding object removal have been proposed in recent years. For example, Y. Wexler et al. proposed the 5-Dimension block search in “Space-time video completion” (IEEE Trans. Pattern Analysis and Machine Intelligence, vol. 29, Issue 3, March 2007), and K. A. Patwardhan et al. proposed an object-background inpainting technology in “Video inpainting under constrained camera motion” (IEEE Trans. Image Processing, vol. 16, Issue 2, February 2007). However, technologies as such are only applicable to object removals with many known pixels around. For example, these technologies are applicable to remove regular movements such as walking movements and objects covering small areas in films. However, these technologies cannot effectively remove objects in films covering a wide range and lacking surrounding information such as moving captions.
Although J. Sun et al. proposed a recovering method for structural regions in “Image completion with structure propagation” (ACM Conf. Comp. Graphics (SIGGRAPH), vol. 24, 2005), this method requires manual completion of structural drawing, and thus automatic structure recovery of the structural region cannot be achieved.
Furthermore, removal techniques for known objects involve high computation, and thus do not meet the requirements for real-time processing. Besides, it is difficult to maintain the consistency of temporal domain and spatial domain. Therefore, a new caption removal method is provided.